Address PR #19 review feedback round 3:

- TrackingData.group_id renamed to room_id (works for both group and DM)
- Removed room_id from TrackedBounty (it's just a lightweight pointer)

core/models.py

@@ -23,16 +23,12 @@ class Bounty:
 class TrackedBounty:
     """A bounty that a user is tracking.
 
-    Use TrackedBounty when you need to record that a user is tracking a specific
-    bounty from a specific room. The room_id indicates which room the bounty
-    was tracked from (useful when users can track bounties across multiple rooms).
-
-    For simple tracking lists, just use bounty_id and created_at.
+    Lightweight relation/pointer - the actual tracking context (including room)
+    lives in TrackingData, not here.
     """
 
     bounty_id: int
     created_at: int
-    room_id: int
 
 
 @dataclass
@@ -50,16 +46,16 @@ class RoomData:
 
 @dataclass
 class TrackingData:
-    """User tracking state within a group.
+    """User tracking state within a room (group or DM).
 
     TrackingData vs TrackedBounty:
-    - Use TrackingData to store ALL tracked bounties for a user in a specific group.
-      It contains the group_id, user_id, and a list of TrackedBounty entries.
+    - Use TrackingData to store ALL tracked bounties for a user in a specific room.
+      It contains the room_id, user_id, and a list of TrackedBounty entries.
     - Use TrackedBounty to represent a single tracked bounty entry within that list.
 
     TrackingData is the container, TrackedBounty is the item.
     """
 
-    group_id: int
+    room_id: int
     user_id: int
     tracked: list[TrackedBounty]